Automatically variable tensioning device for draw-off reels



June 11, 1935. M. RlCHTER 2,004,219 I AUTOMATICALLY VARIABLE TENSIONING DEVICE FOR DRAW-OFF REELS Filed Nov. 25, 1931 2 Sheets-Sheet 1 IN V EN TOR.

. mm mm; BY

ATTORNEYS.

June' 11 1935. M. RICHTER 2,004,219

AUTOMATICALLY VARIABLE TENSIONING DEVICE FOR DRAW-OFF REELS Filed Nov. 25, 1931 2 Sheets-Sheet 2 77 IN VEN TOR.

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A TITORNEYS.

Patented Julie 11, 1935 PATE T OFFICE AUTOMATICALLY VARIABLE TENSIONING DEVICE FOR DRAW-OFF REELS 'Max Richter, West Reading, Pm, assignor to Textile Machine Works, Wyomissing, Pa., a corporation of Pennsylvania Application November 25, 1931, Serial No. 577,204

18 Claims.

My invention relates to full fashioned knitting machines and particularly to means for automatically varying the tension applied to the fab ric by the usual draw-off reel of such machines.

It is necessary in'knitting full-fashioned fabrics, such as stockings, to vary the fabric tension during the knitting process in order to knit loops of uniform size throughout the length of the stocking. Full-fashioned stockings are narrowed in the course of knitting and hence do not require so great a fabric tension as the length increases and the provision of a uniform tension would result in knitting loops of various sizes. Heretofore, such variations in tension as are necessary have been effected by adding or removing weights for increasing or decreasing the tension on the fabric, such weights being usually suspended on a cable I, acting on the draw-01f reel. In most cases it has been necessary to add or remove the weights by hand, thus requiring attention by the machine operator and involving an expenditure of time which might otherwise be devoted to the supervision of other parts of. the machine. In addition, such weight actuated tension devices are cumbersome and take up considerable space because it is necessary to provide for suflicient weight travel to permit the tensioning device to act on the draw-off reel throughout the knitting of the entire length of the stocking.

In carrying out my invention I provide a plurality of springs any number of which may be initially operatively connected to the draw-off reel to provide the desired fabric-tension and which may be successively and automatically disconnected from the draw-off reel to vary the fabric tension at desired times in the knitting process. I utilize relatively short springs connected to the draw-01f reel for providing the desired fabric tension and inasmuch as short springs are effective to cause only a limited angular movement I provide means for rendering the springs effective to cause the required rotative movement of the reel. I also provide for holding the reel in the rotative position to which it has been moved by the springs and further provide for the release of the spring tension when this is necessary during restoration of the springs to insure continued rotative movement of the draw-off reel or is otherwise desirable during operation of the knitting machine.

A feature of. my invention resides in the provision of spring means acting on the draw-off reel of a full fashioned knitting machine to produce the desired fabric tension.

A second feature resides in automatically varying the spring tension during the knitting process.

A third feature resides in reducing the space occupied by actuating devices for the draw-off 5 reel in a knitting machine.

A fourth feature resides in utilizing relatively short springs to turn the draw-off reel and compensating for the limited angular movement effected by such short springs.

A fifth feature is the provision of means for relieving the fabric tension at certain times in the knitting process.

A sixth feature is the provision of means for holding the draw-off reel in its rotated position to prevent development of slack in the fabric.

Other features and advantages will be apparent upon consideration of the following description and claims when read in conjunction with the accompanying drawings in which:

Figure 1 is an end view of a portion of a full fashioned knitting machine embodying my invention;

Fig. la is a diagrammatic front view illustrating certain details of Fig. 1.

Figure 2 is a front view of portions of the knitting machine.

Figure 3 is a longitudinal sectional view of a combined clutch and brake associated with the draw-off reel of a full fashioned knitting machine;

Figure 4 is a sectional view of the brake on the line. 4-4 in Fig. 3;

Figure 5 is a sectional view, taken on the line 55 in Fig. 3, of the clutch.

Referring to the drawings, the numeral 10 designates the usual draw-off reel which is rotatively biased to maintain the fabric ll under tension While drawing the fabric from the needles I! as it is knit in well known manner on a full fashioned knitting machine. Suitable bearings, not shown, are provided for journalling a shaft l3 on which reel I0 is fixedly mounted.

As shown in Figures 3 and 5, also fixed to shaft i3 is the part M of a ball clutch 29, the complementary part l5 of which is adjustably connected to a surrounding sleeve l6 by a spring pressed plunger 11. As best seen from Fig. 5, clutch members 14 and I5 have a plurality of coacting surfaces 5 and 6 which diverge relative to each other and between each pair of these surfaces is a roller or pin member I biased by means of spring members 8 into wedging engagement with the surfaces 5 and 6, so that upon rotation of the member IS in clockwise direction, as viewed in Fig. 5, the clutch members I4 and 5 are in locked engagement and rotate as a unit. When member I5 is rotated in a counter-clockwise direction, however, the'curved surface 6 is rotating in a direction such that it tends to provide the requisite clearance between that surface member and wedge member 1 and thus member i5 may rotate freely in this direction relative to member 4. Clutch part I5 and sleeve l6 are rotatively mounted in a groove between the flange IQ of a collar l9, secured to shaft l3'with clutch part I4, and a spacing ring 20 which is connected to a bracket 2| and supported on shaft l3 by a ball bearing 22. A lever 23 on sleeve I6 is connected to one end of a chain or other flexible member 24 to which tensioning devices are applied for operating clutch l4, l5 to maintain reel ||l under desired tension. Lever 23 is also connected to a spring 25 anchored on a bracket 26 for reversely operating the clutch to obtain a new operating purchase on shaft 3 when the tension is released.

Chain 24 extends over guide rollers 21 mounted on brackets 2| and 38 and is adjustably attached at its other end toa clevis 3| connected to a yoke member 32 by a pin 33, the ends of pin 33 extending beyond the sides of clevis 3| for a purpose which will later be described. Yoke 32 supports a stud 34 on which a plurality of latches 35 are loosely mounted in side by side relation between the bifurcations of the yoke. Latches 35 are connected by individual springs 36 to levers 31 pivoted intermediate their ends on a stub shaft 38 supported by spaced lugs 40 on projecting portions 4| of an arm 42 of bracket 38. One end of each lever 31 engages a shoulder or lug 43 on the related latch 35 and their other ends are connected to individual springs 44 also connected to an anchoring pin 45 on bracket 30. The levers 31 are provided with a plurality of notches 46 so that springs 44 may be adjustably connected thereto to exert a varying pull which is transmitted to chain 24 through the engagement of the ends of levers 37 with the shoulders 43 on the latches 35, which provide a releasable connection between the springs and chain as will hereafter appear.

From the foregoing it will be seen that the aggregate adjusted force of springs 44 is transmitted through levers 31, latches 35 and chain 24 to clutch part |5 which acts on the part I4 thereof to turn shaft l3 and draw-off reel ID for drawing fabric under tension from needles |2. During the knitting of a full fashioned fabric such as a stocking it is desirable at times to relievethe tension on the draw-off reel. For this purpose I provide a bell crank 41 pivoted on bracket 3|l-and having an arm 48 supporting a roller 48a engageable by cams 49 or 58 on the usual cam shaft 5|. The other arm 52 of the bell crank has bifurcations 53 extending beneath the projecting ends of the pin 33 which connects clevis 3| to yoke 32 so that when the bell crank is rocked, either by cam 49 or by cam 58, the bifurcations 53 engage pin 33 and raise yoke 32. Thus, chain 24 and consequently draw-oil reel l0 may be relieved of the tension exerted by the springs 44 operatively connected to the yoke.

Inasmuch as the angle through which springs 44 may move lever 23 to turn draw-off heel I8 is limited, it is desirable to reset clutch 29 at intervals. This is effected by spring 25 which acts when the chain 24 and lever 23 are relieved of the tension of springs 44, as described above, to move clutch part |5 reversely in order to obtain a new operating purchase on shaft 3 through clutch part l4. A brake 54 is provided to maintain draw-off reel ID in the position to which it has been turned in order to prevent the development of slack in the fabric when the clutch is reset.

As best shown in Figures 3 and 4, brake 54' comprises a brake drum 55 fixed to shaft l3 and enclosing a brake shoe comprising a split ring 56. Between the ends of brake shoe 56 is the squared end 51 of a stud 58 pivotally mounted in the ring 20 which spaces brake 54 from clutch 29. A brake operating lever 60 is secured to stud 58 and projects from. ring 20 to be engaged by the end of an arm 6| of a bell crank 62 pivoted on bracket 30. The arm 63 of the bell crank carries a roller 63a engageable by a cam 64 on cam shaft 5| for operating bell crank 62 to cause the end of arm 6| thereof to engage and actuate lever 68 to apply brake 54.

A spring 65 connecting the arms 48 and 63 of bell cranks 41 and 62, respectively, maintains the rollers 48a and 63a. carried thereby in engaging relation with the associated cams on the cam shaft, an adjustable stop 66 also being provided for arm 63. The cam shaft 5|, during its usual axial movement in narrowing operations, moves cam 49 from engagement with the roller 48a of arm 48 of bell crank 41 and positions cam 50 to operate bell crank 41, by engagement of said cam 58 with the roller 48a. The brake 54, normally operated through the bell crank 62 and roller 63a, will thus be rendered inoperative by reason of the disengagement of the roller 63a and cam 64 (see Fig. 1a). At such time the brake will be held in its idle position by engagement of the arm 63 with the adjustable stop 66. By the means just described, the tension releasing means will be operative in both narrowing and plain knitting positions of the cam shaft, while the brake will be operative only in the plain knitting position.

As mentioned above, in knitting a full fashioned stocking less tension is required as the length increases because of the narrowing of the fabric. Accordingly I have provided mechanism for automatically varying the fabric tension at desired times'during the knitting process. A drum 19 secured to a shaft 1| mounted in the projections 4| of arm 42 on bracket 30 is provided with a plurality of studs 13 arranged axially and peripherally of the drum, a stud being provided for engaging and moving each of the latches 35 to release the end of the associated lever 31 and disconnect the corresponding spring 44 from chain 24. An arm 14 loosely mounted on shaft H carries a pawl I5 engaging a ratchet 16 fixed to the shaft and is connected to a rod H by a lever 18 pivoted on bracket 38. Rod 11 extends through a guide 89 and is connected to a lever 8| pivotally mounted on a bracket 82 and having a lug 83 engageable by buttons 84 on a pattern chain 85 guided over a rotatively mounted sprocket 86.

A bail 81 extends beneath levers 31 for restoring the ends of thelatter to engagement with the shoulders 43 of latches 35. Bail 81 is supported by arms 88 and 89 secured to shaft 38. A lever 90, which may be a continuation of arm 89, is provided for raising the bail, which is normally held away from levers 31 by a spring 9| connected to arm 89.

In operation, the springs 44 may be adjusted in the notches 46 of levers 31 to exert varying forces and as many of the levers as are required to provide the desired initial fabric tension have their ends engaged with the shoulders 43 of latches 35 to operatively connect the springs 44 to chain 24 and draw-oil reel l0. Springs 44 then act on lever 22 to turn shaft i3 and rotate draw-on reel ill to draw the fabric H from needles l2. n each 1 revolution of cam shaft 5| cam 48 rocks bell crank 4'! raising yoke 32 to relieve chain 24 from the tension of springs 44. Bell crank 62 is also rocked by cam 64 to operate lever 80 and applybrake 54'to hold shaft i3 and reel iii in their rotated position as spring 25 acts on lever 23 for reversely operating clutch 29 to obtain a new operating purchase on shaft 13. Thus, although the angle through to the reel requiredto maintain a stocking under tension throughout the knitting of "the entire length thereof. v

Pattern chain 85 is intermittently advanced in well known manner on rotation of cam shaft 5i during the knitting process and each time that a button 84 engages lug 83 lever Si is rocked moving rod I1 and levers l8 and 14 to cause pawl 15 to advance ratchet I6 and turn drum 10. On each step movement ofdrum 10, a stud I3 thereon engages the corresponding latch 35 and moves the latter from contact with the end of the associated lever 31. Thus, the springs 44 are individually disconnected from chain 24 to reduce the tension acting on draw-off reel in and consequently reduce the fabric tension at various times as the knitting of the fabric progresses. The amount by which the fabric tension is reduced at any time depends on the force normallyexerted by the spring which is disconnected and this in turn is determined by the adjustable connection of the springs 44 in the notches 46 of the levers 31. If desired several of the springs may be simultaneously disconnected to reduce the fabric tension. It will be apparent that the adjustable connection of springs 44 to levers 3! provides for a nicety of adjustment which together with the capability for releasing several springs simultaneouslyas well as successively enables reduction of the fabric tension by varying desired amounts at various stages of the knitting process.

When cam shaft Si is shifted axially in narrowing, as is usual, the cam 49 is moved from engagement with the roller 48a of hell crank 4'! and the cam 50 acts to rock the bell crank for raising yoke 32 to relieve the tension applied to the fabric through draw-off reel Ill during narrowing. Cam 641s also moved from engagement with the roller 63a of brake operating bell crank 62 so that brake 54 is not applied during narrowing.

The improvements specifically shown and described, by which the results above set forth are obtained, may be modified in various ways, without departing from the spirit and scope of the invention as disclosed. and as set forth in the appended claims.

What I claim is:

1. In a knitting machine including mechanism for laying and preselecting the laying of thread courses, a fabric draw-off reel, means associated with said reel for applying tension thereto, and mechanism responsive to operation of said courseselector mechanism in accordance with a selection thereof for causing said tensioning means to apply different degrees of tension to said reel during the knitting of different portions, respectively, of said fabric.

2. In a knitting machine, a pattem-control mechanism, a knitting mechanism, a fabric takeoff device, means including a source of variable force releasably connected to said device for yieldingly biasing the same to tension the fabric, cooperating means for rendering said biasing means ineffective to affect the fabric, and means controlled by said pattern-control mechanism in accordance with a pattern for actuating said biasing means to vary the tension on the fabric in a manner to be unaffected by the fabric.

3. Ina straight knitting machine, the combination of loop forming mechanism, a cam shaft controlling said mechanism, fabric take-oil mechanism operating in time relation with respect to said cam shaft, means for applying tension to said take-oil mechanism, and mechanism controlled by, and operative after a predetermined number of revolutions of, said cam shaft for causing said tension means to apply difierent degrees of tension to said take-off mechanism during the knitting of different portions respectively of the fabric.

4. In a knitting machine including a draw-0E device, tensioning spring means, means operatively connecting said spring means to said device, and means for automatically affecting one or more elements of said spring means to vary the tension applied to said device.

' 5. In a knitting machine having a pattern chain; a draw-off reel; a plurality of tensioning devices; means including latches for severally connecting said tensioning devices to said reel; and means controlled by said pattern chain for automatically and successively releasing said latches to progressively vary the tension applied to said reel by said tensioning devices.

6. In a knitting machine having a draw-oil reel, a plurality of tensioning springs, means operatively connecting said springs to said reel; means for automatically disconnecting one or more of said springs to reduce the tension applied to said reel; and means for resetting one or more of said disconnected springs.

7. In a knitting machine having a draw-02f reel; a plurality of tensioning devices; means including latches for severally connecting said tensioning devices to said reel; and means for automatically and successively releasing said latches to progressively vary the tension applied to said reel by said tensioning devices.

8. In a straight knitting machine, the combination of loop forming mechanism, a cam shaft controlling said mechanism, fabric take-off mechanism operating in time relation in respect to said cam shaft, means for applying tension to said take-ofi mechanism, and mechanism controlled by the shaft in preselected courses during the the stocking blank for progressively decreasing the tension applied to the fabric by said take-off mechanism.

10. In a straight knitting machine, the combination of loop forming mechanism, a cam shaft controlling said mechanism, fabric take-off mechanism operating in time relation with respect to said cam shaft, means for applying tension to said take-offmechanism, a plurality of tension devices for actuating said take-off mechanism in a direction to draw off the fabric, and mechanism controlled by, and operative after a predetermined number of revolutions of, said cam shaft for selectively operating said tension devices to apply different degrees of tension to said take-off mechanism during the knitting of different portions respectively of the fabric.

11. In a knitting machine having a draw-off reel; a plurality of tensioning springs; means operatively connecting said springs to said reel; and means for automatically disconnecting one or more of said springs to reduce the tension applied to said reel.

12. In a knitting machine; a draw-off reel; a plurality of levers operatively connected to said reel; and tensioning means adjustably connected to said levers for exerting varying forces on said reel.

13. In a knitting machine; a draw-off reel; a plurality of levers, means including latches for operative-1y connecting said levers to said reel; means adjustably connected to said levers for exerting varying tensioning forces onsaid reel;

and means for releasing said latches to reduce the tension applied to said reel by varying amounts during the knitting process.

14. In a straight knitting machine, the combination of a cam shaft, a loop forming mechanism including a series of knitting needles, a series of loop forming points adapted to engage selected ne-edles to produce loops caused by coaction between said points and needles, fabric takeoff mechanism for applying tension to the fabric, tension means yieldably connected to said takeoff mechanism for urging said take-off mechanism in a direction to draw off the fabric, mechanism controlled by the cam shaft in preselected courses during the knitting of the stocking blank for causing said tension means to apply different degrees of tension to the take-off mechanism during the knitting of the different portions respectively of said fabric, and mechanism for automatically releasing the tension applied to the take-off mechanism during coaction between the loop engaging points and selected needles.

15. In a knitting machine; a cam shaft; a drawofl' reel; a uni-directional clutch associated with said reel; tensioning means including a spring and yieldably connected to said clutch through said spring for biasing the same toturn said reel turning of said reel; cam shaft controlled means distinct from said resetting means controlling said tensioning means for relieving said clutch of the tension applied thereto to enable resetting thereof; a brake associated with said reel; and cam shaft controlled means for operating said brake to hold said reel in its rotated position during resetting of said clutch.

16. In a knitting machine having a draw-off reel; tensioning means including a spring and yieldably connected to said reel through said spring for rotating the latter'under tension; a cam shaft; cam shaft controlled means for operatively disconnecting said tensioning means from said reel and for storing energy in said tensioning means; and a cam shaft operated brake for holding said reel in its rotated position during the storing of energy in said tensioning means, and means adapted to automatically vary the effect of said stored energy of the tensioning means upon the fabric being knitted.

17. In a knitting machine having a cam shaft shiftable from a knitting position to a narrowing position, a draw-off reel and tensioning means yieldably connected to said reel for rotatively operating the latter under tension; means operable to relieve said reel of the tension applied thereto by said tensioning means; means operable to hold said reel in its rotated position on said relief of tension; cam means on said cam shaft operative in either position of said shaft for operating said tensioning means to relieve said reel of tension; and cam means on said cam shaft operative only in the knitting position of said shaft for operating said holding means to hold said reel in its rotated position.

18. In a knitting machine; a draw-ofi reel; a uni-directional clutch associated with said reel; biasing means including a spring and yieldably connected to the driving member of said clutch through said spring for turning said reel through a predetermined angle and means for automatically varying the effect of said biasing means; means for resetting said clutch for causing said biasing means to effect further turning of said reel; a cam shaft and cam shaft controlled means distinct from said resetting means controlling said biasing means to enable resetting of said clutch in each course of the fabric as itis knit.

MAX RICHTER. 

